This invention pertains to wobble piston assemblies, such as are employed in inexpensive air compressors and the like, and in particular to an assembly of the aforesaid type in which a seal retaining ring and the piston have surfaces conformed to facilitate their assembly, and cooperative to define a void therebetween in which to accommodate an extruded expansion of an innermost, peripheral edge of a cup-type seal, to enhance a retention of the seal about the piston.
Wobble piston assemblies are well known in the prior art, and commonly they comprise a piston having a cup-type seal fixed thereabout by a retainer of some sort. Typically, the retainer is set upon the seal to secure it against displacement.